Asymmetric Synthesis of β-Methylated Aliphatic Ketones via Lithiated 3-[(S)-2-(Methoxymethyl)pyrrolidino]hex-3-ene☆

✍ Scribed by Hubertus Ahlbrecht; Rainer Schmidt; Uwe Beyer

• Book ID: 101276256
• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 332 KB
• Volume: 1998
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199807)1998:7<1371::aid-ejoc1371>3.0.co;2-k

✦ Synopsis

3-Substituted aliphatic ketones 10 have been obtained in of the 3-stannylated enamine 7a with butyllithium. An improved hydrolysis procedure for the resulting enamines is excellent optical yields by alkylation of the aminoallyllithium compound endo-8, a homoenolate equivalent of hexane-3-described. Some mechanistic implications with respect to the formation as well as the alkylation of endo-8 are discussed. one, using prolinol ether (SMP) as the chiral auxiliary. The intermediate endo-8 was generated by tin-lithium exchange